广西茅尾海潮间带表层沉积物有机物特征及来源分析

Characteristics and sources of organic matter in surface sediments of the intertidal zone in Maowei sea,Guangxi

为研究广西钦州湾茅尾海潮间带表层沉积物有机质中烃类化合物的分布特征及来源,本文于2019年10月采集茅尾海潮间带表层沉积物样品6件,对沉积物中的正构烷烃和多环芳烃(PAHs)进行分析。结果表明,茅尾海潮间带表层沉积物样品中正构烷烃的含量(干重)为1835.6×10^(−9)~5661.6×10^(−9),PAHs含量(干重)为39.45×10^(−9)~138.12×10^(−9),总体处于含量较低的水平;参数比值法分析结果显示,正构烷烃主要来源于陆源草本植物、木本植物及浮水植物;PAHs具有大分子化合物占优势的特征,组分分析法结果指示PAHs主要来源于煤、草木等的燃烧;应用效应区间低/中值法对PAHs进行生态风险评价,结果表明,PAHs生态风险处于较低水平。

In order to study the characteristics of the distribution and sources of hydrocarbons in organic matter in the surface sediments of the intertidal zone in Maowei sea,Guangxi.Six samples of surface sediments which were collected from the intertidal zone of the Maowei sea in October 2019 were analyzed in terms of the contents of the n-alkanes and PAHs.The results show that the content of n-alkanes(dw)in the surface sediments of intertidal zone of Maowei sea is 1835.6×10^(−9)~5661.6×10^(−9),and the content of PAHs(dw)is 39.45×10^(−9)~138.12×10^(−9).Generally,the contents of n-alkanes and PAHs in the surface sediments of intertidal zone of Maowei sea is low.The parameter ratio analysis shows that the n-alkanes mainly come from terrestrial herbaceous plants、woody plants and floating plants,whereas PAHs are characterized by high level of macromolecular compounds.The results of component analysis suggest they mainly come from the combustion of coal,grass,tree,and so on.The assessment report of the ecological risk about PAHs using the ERL/ERM shows that the overall risk of PAHs is in a low level.